Elucidation of gully erosion characteristics considering the periodicity of unevenness on embankment crest
| Project/Area Number |
19K04611
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Multi-year Fund |
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| Section | 一般 |
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| Review Section |
Basic Section 22040:Hydroengineering-related
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| Research Institution | Saitama University |
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Principal Investigator |
Yagisawa Junji 埼玉大学, 理工学研究科, 准教授 (70549998)
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| Project Period (FY) |
2019-04-01 – 2022-03-31
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| Project Status |
Completed (Fiscal Year 2021)
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| Budget Amount *help |
¥4,420,000 (Direct Cost: ¥3,400,000、Indirect Cost: ¥1,020,000)
Fiscal Year 2021: ¥910,000 (Direct Cost: ¥700,000、Indirect Cost: ¥210,000)
Fiscal Year 2020: ¥1,040,000 (Direct Cost: ¥800,000、Indirect Cost: ¥240,000)
Fiscal Year 2019: ¥2,470,000 (Direct Cost: ¥1,900,000、Indirect Cost: ¥570,000)
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| Keywords | 河川堤防 / 越流 / ガリー侵食 / 堤防天端の凹凸の周期性 / 堤防越流侵食 / 堤防天端凹凸波長 / 天端凹凸波長 / 堤防越流 / 天端上凹凸の周期性 |
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| Outline of Research at the Start |
越流により生じる裏法面のガリー侵食は，特に越流初期の裏法面の地形を決めるとともに，侵食箇所への流れが集中することで，その後の堤体侵食過程や破堤までの時間，すなわち堤防の粘り強さにも大きな影響を与えることが予想される．しかし，従来の堤防の越流侵食に関する研究では，この初期地形の形成過程は十分に考慮されていない．本研究では，越流初期に生じるガリー侵食の特性を，越流水深，堤防天端の縦断的な凹凸の周期性，堤体材料特性，裏法勾配と関連付けることで，越流後，早期に破堤に繋がるリスクの高い箇所を明らかにする．
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| Outline of Final Research Achievements |
The purpose of this study is to clarify the high-risk points leading to the levee breakage at an early stage, considering the overflow water depth, the periodicity of the longitudinal unevenness of the top of the levee, and the difference in the back slope.
As a result of experiments and numerical analysis, it was clarified that there is a peak uneven wavelength in which the scale of gully erosion (erosion depth) and the distance between adjacent gully are shortened even if the overflow conditions are the same.
This suggests that it is useful to grasp the weak points where the risk of early levee breakage is high by grasping the wavelength of the top unevenness at the points where the risk of overflow is high.
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| Academic Significance and Societal Importance of the Research Achievements |
従来堤防越流を伴う侵食に関する研究は，堤防形状を理想化した状態での評価に留まる研究が多い．本研究では，堤防天端に生じる縦断的な凹凸を考慮した上で，生じるガリー侵食の特性を把握できるため，その学術的意義は高い．本研究で得られた知見は，現存する堤防の越流危険箇所に対して天端の凹凸の状況を把握することで，堤防天端の効率的な補修計画に大きく貢献できると期待され，本研究の工学的，社会的意義は非常に高い．
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Report
(4 results)
Research Products
(5 results)
